Vacuum air-pump.



P. SGHOU.

VACUUM AIB PUMP.

APPLIoATIoN FILED umso, 1913.

Patented Nov. 17, 1914.

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PAUL SCHOU, OF COPENHAGEN, DENMARK.

VACUUM AIR-PUMP.

Application filed January 29, 1913.

To all 'whom t may concern.'

Be it known that I, PAUL Sonori, of 11 Puggaardsgade, Copenhagen, in theKingdom of Denmark, have invented certain new and useful Improvements inVacuum Air- Pumps, of which the following is a specification, referencebeing had therein to the accompanying drawing.

This invention relates to vacuum pumps of the type in which, to insurecomplete discharge of' air and vapor at each stroke, a small quantity ofoil from an oil reservoir in which the pump crank and connecting rodworks is allowed to pass under the influence of the pressure of theatmosphere upon the oil in the reservoir, into the cylinder above thepiston, the discharge valve, which is oil sealed, being at the top ofthe cylinder.

According to this invention the cylinder is formed with an annularsuction passage into the lower part of which, upon the downward strokeof the piston, oil passes from the oil reservoir and through theclearance space between the lower part of the piston and the cylinder,and from which oil flows onto the top of the piston when at the lowestpoint ot' its stroke, the upper part of the said suction passage beingin free communication with the suction pipe and the upper end of thecylinder being provided with an annular oil bath that forms a fluid sealto the discharge valve and into which the oil from the cylinder iscaused to pass as the piston reaches the highest point in its stroke,oil overflowing from the said 'annular bath passing down into the saidoil reservoir.

A vacuum pump embodying the invention is shown in the accompanyingdrawing.

Figure l shows a vertical section with the piston at the upper end ofthe stroke, and Fig. 2 shows a` vertical section with the piston at thelower end of the stroke.

rlie cylinder l depends downwardly into the oil contained in an oilreservoir Q in which the crank pin 3 and the connecting rod l work, thelevel of the lubricating oil in the reservoir being such that the lowerend of the piston dips into the oil even when the piston is at the topof its stroke. vWhen the piston descends the oil displaced thereby isforced up into the annular space 6 around the cylinder. The space 6 andoil reservoir 2 are in communication with the atmosphere and as thepressure in the cylinder l is considerably below atmospheric Specicatonof Letters Yatent.

Serial No. 744,806.

pressure, a small portion of the oil will be forced by atmosphericpressure into the.

cylinder' and into the annular passage 10 which forms the suctionchamber of the pump, as the piston makes its downward strokes. At itslower portion, the piston is so ground that it lits somewhat loosely inthe cylinder, the space being so minute as to be imperceptible on thedrawings, whereby the atmospheric pressure enables the oil to pass tothe said chamber lO, any method of' relatively grinding the cylinder andpiston so that the oil can pass between them would serve. Each time thepiston reaches the lowest point of its stroke oil from the passage l0liows into the cylinder above the piston and is expelled at the top ofthe cylinder together with the air immediately the piston lifts thecover or valve 7 the flange of which is formed with holes 8. The oil soexpelled passes into an annular oil bath 9 embracing the cover. Theupper edge of this oil bat-h is situated at such a height that the levelof' the oil is always above the holes 8 in the cover. If when the pistonis in its lowest position oil is charged into the reservoir and space 6up to the level of the filling plug l1 this will be the correct chargeof oil. Oil flowing over the upper edge of the pocket 9 falls back intothe reservoir 2 and space 6.

Having now particularly described and ascertained the nature of the saidinvention and in what manner the same is to be performed I declare thatwhat I claim is:

1. In a pump, the combination of a cylinder connected with an oilreservoir, a piston reciprocating in said cylinder, and fitting looselyin the cylinder at the portion adjacent to said reservoir, and pressuremeans connected with said reservoir, whereby the oil can be driventhrough the space between the said piston and the said adjacent end ofsaid cylinder, above the piston, when the piston is in said adjacent endof said cylinder, to form a seal.

In a vacuum pump, the combination of a. cylinder connected with an oilreservoir, a piston reciprocating` therein, and fitting loosely in thecylinder at the portion adjacent to said oil reservoir, said oilreservoir communicating with the atmosphere, said piston being at theend of its rarefying stroke when in the said adjacent end of saidcylinder, whereby the pressure of the atmosphere then drives the oilthrough the space Patented Nov. 17, 1914.,

mediate said induction pipe and said cylin-v der.v means for placing andmaintaining a liquid seal in said intermediate channel, when the pistonis removing charge oi gas received through said induction pipe and theinduction pipe is disconnected from the cylinder, and means for removingsaid liquid seal when said cylinder is receiving a charge of gas fromsaid induction pipe and is connected therewith.

In a vacuum pump, the combination oi' a cylinder, an induction pipe, achannel intermediate said induction pipe and said cylinder, adischarge-valve in said cylinder, a

piston having side walls of greater length than the distance betweensaid dischargevalve and said channel, a reservoir or' liquid connectedto said cylinder, the end of the piston fitting loosely in the cylinderadjacent the said reservoir, the piston head being below said channelsat the end of the exhaust stroke, said reservoir having connnunicationwith the atmosphere, whereby the atmospheric pressure drives the liquidinto said channels, when the piston is above said channels.

6. In a vacuum-pump, the combination of a cylinder, an induction pipe, achannel intermediate said induction pipe and said cylinder, adischarge-valve in said cylinder, a piston having side-walls of greaterlength than the distance between said dischargevalve and said channel, areservoir of liquid connected with said cylinder, the piston, at the endof its stroke, having its head `below said channels and dipping into thesaid reservoir, said piston iitting loosely in that part of the cylinderadjacent said reservoir, said reservoir having communication with theatmosphere, whereby the pressure of the atmosphere drives the liquidfrom the reservoir into said channel, to be then driven by the gasexhausted upon the piston-head.

7. In a pump, the combination of a cylinder, side-channels intermediatesaid cylinder and an induction pipe a piston, a reservoir of liquidconnected to said cylinder, said piston litting loosely in that end ofthe cylinder adjacent said reservoir, means for drivingliquid from saidreservoir through the space between the piston and the cylinder, whenthe piston is in the loosely fitting part into said side channels saidliquid being driven upon the piston-head when it is vbelow said channelsby the gas entering through-said induction pipe, a dischargevalve in thetightly fitting part of the cylinder, a cap aro-und said discharge-valveadapted to receive and hold the liquid driven therethrough, and meansfor returning overflow liquid from said cap to said reservoir.

S. In a vacuum pump, the combination of a cylinder, having adischarge-valve, a cap around said discharge-valve a piston, aninduction pipe, a reservoir of liquid connected to said cylinder, meansfor placing and maintaining a liquid seal from said reservoir in saidinduction pipe when said piston is expelling a charge of gas drawnthrough said induction pipe, means for withdrawing said liquid seal whensaid piston has eX- hausted said cylinder and is below said channel,means for carrying said liquid seal when withdrawn, through saiddischarge-valve and into said cap around said dischargevalve, and meansfor carrying the overflow from said cap into said reservoir.

9. In a vacuum pump, the combination of a cylinder, an induction pipe, achannel in-` termediate said induction pipe and said cylinder, adischarge valve in said cylinder, a piston having side walls of greaterlength than the distance between said dischargevalve and said channel, areservoir of liquid connected to said cylinder, the end of the pistonfitting loosely in the cylinder adjacent said reservoir, the piston-headbeing below the channels at the end of the stroke, said reservoir havingcommunication with the atmosphere, whereby the atmospheric pressuredrives the-liquid into said channels while the induction pipe isdisconnected from the cylinder, the liquid being driven by the gasexhausted upon the piston-head and carried by said head of the pistonand forced through said discharge-valve, a cap around thedischarge-valve to receive and hold said liquid, and means for returningthe overflow from said cap into said reservoir.

In testimony that I claim the foregoing as my invention, I have signedmy name in presence of two subscribing witnesses.

rant sonori.

Vi tnesses P. I-IOFMAN BAUG, I-IJALMAR BoN'rARD.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. C.

